package com.aaa.dang.common.util;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import java.net.InetAddress;
import java.net.UnknownHostException;

/**
 * 专门用来存储和获取session信息
 * @作者： Dadazhao
 * @时间： 2018-10-23 上午8:37:59
 * @作用：
 * @描述：
 */
public class SessionUtil<T>{
	/**
	 * 从请求中获取session对象
	 * @return
	 */
	public static HttpSession getHttpSession(){
		HttpSession session = null;
		session = getRequest().getSession();
		return session;
	}
	/**
	 * 从请求上下文中获得请求对象
	 * @return 
	 */
	public static HttpServletRequest getRequest(){
		ServletRequestAttributes attr = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
		return attr.getRequest();
	}

	/**
	 * 获得请求的ip地址
	 * @return
	 */
	public static String getIP(){
		HttpServletRequest request = getRequest();
		String ipAddress = null;
		try {
			ipAddress = request.getHeader("x-forwarded-for");
			if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
				ipAddress = request.getHeader("Proxy-Client-IP");
			}
			if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
				ipAddress = request.getHeader("WL-Proxy-Client-IP");
			}
			if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
				ipAddress = request.getRemoteAddr();
				if (ipAddress.equals("127.0.0.1")) {
					// 根据网卡取本机配置的IP
					InetAddress inet = null;
					try {
						inet = InetAddress.getLocalHost();
					} catch (UnknownHostException e) {
						e.printStackTrace();
					}
					ipAddress = inet.getHostAddress();
				}
			}
			// 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
			if (ipAddress != null && ipAddress.length() > 15) { // "***.***.***.***".length()
				// = 15
				if (ipAddress.indexOf(",") > 0) {
					ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
				}
			}
		} catch (Exception e) {
			ipAddress="";
		}
		ipAddress = getRequest().getRemoteAddr();
		return ipAddress;
	}

	/**
	 * 设置session
	 */
	public static <T> void setSession(String sname,T obj){
		getHttpSession().setAttribute(sname, obj);
	}
	/**
	 * 得到session
	 * @param sname
	 * @return
	 */
	public static <T> T getSession(String sname){
		return (T) getHttpSession().getAttribute(sname);
	}
	/**
	 * 销毁session
	 * @param
	 */
	public static void removeSessiom(){
		HttpSession session = getHttpSession();
		session.invalidate();
	}
}
